Method and equitment suitable for the formation of cut tobacco strands in cigarette making machines



Jan. 16, 1962 A. SCHMERMUND 3 6,904

9 METHOD AND EQUIPMENT SUITABLE FOR THE FORMATION OF CUT TOBACCO STRANDSIN CIGARETTE MAKING MACHINES Filed March 9, 1960 Qumnnnn United StatesPatent 3,016,904 METHOD AND EQUIPMENT SUITABLE FOR THE FORMATION OF CUTTOBACCO STRANDS IN CIGARETTE MAKING MACHINES Alfred Sehmermund,Maschinenfabrik Alfred Schmermund, Gevelsberg, Westphalia, Germany FiledMar. 9, 1960, Ser. No. 13,770 Claims priority, application Germany Mar.16, 1959 14 Claims. (Cl. 131--66) A well known method for the tournationof cut to bacco strands as required in cigaretteniaking machines is toproduce such strands by the use of mechanical means in the form of atobacco spreader. In the case of such conventional cigarettennakingmachines, tobacco is taken from a storage container, by means of toothedcylinders as well as belts; then, a tobacco fleece is formed, the singletobacco particles of which fall down onto a continously running conveyorbelt. The result is a tobacco strand which, with respect to weight,corresponds to the cigarettes to be produced, and which, in a well-knownmanner, is enveloped by paper. After the paper has been glued along theseam, the paper-wrapped tobacco strand will be cut so as to obtain thewanted cigarette lengths. The machinery for this method requires a largearea and the resultant strands have portions of highly differentdensities.

In another known method, porous conveyor belts are used. In such case,tobacco is brought onto the porous endless belt by means of a continuousair current, and, for the most part, in an upward direction. Thus, thetobacco being treated adheres to the face of the lower part of the beltconcerned, as a result of the air pressure; the stream of air escapingthrough the belt. All tobacco contains moisture, sticky substances anddust. Such form obstructions upon the porous belt, thereby reducingworking efiiciency.

The principal object of this invention is the use of novel electrostaticequipment for the production of a uniform tobacco strand.

In accordance with the present invention cut tobacco is subjected to ahigh static direct current voltage potential. Over the tobacco fleece,is disposed a continuously driven conveyor belt which operates as anintermediate carrier. As a result of their special potential, thetobacco fibers (flocky particles) will be passed over onto the belt faceand adhere to it in the form of a uniform coat, and in accordance withthe existing field intensity, and will finally leave the electrostaticfield and be conducted onto a second continuously running belt in theform of a uniform tobacco strand. Subsequently, the tobacco strand maybe rendered more dense or compacted by the use of known means. Then, thepaper may be applied, glued along the seam, and the ready-preparedpaper-wrapped tobacco strand may be cut so as to produce the wantedcigarette lengths.

The present invention oifers some considerable advantages. For instance,the voltage, and, consequently, the field intensity, may be adjusted andcontrolled in a very easy manner, and, as a result of this, the weightper length unit of strand-may be regulated accordingly, as per theactual service requirements. Also the equipment requires a relativelysmall space and has high efficiency in operation. It operates in aconstant and uniform manner since the service or operating conditionsremain unchanged and the high voltage can be uniformly maintained byknown automatic control devices. The current consumption is extremelylow; the current intensity being measured in microamperes (ranging fromabout 100 to 1,000 microamperes).

A still further advantage of the present invention is that there will beno injury hazard to operators, since, when a maximum current intensityof about 2 milliamperes has been reached, the equipment may be cut outautomatically,

within the very short time of 2 microseconds, and because it is safelyprotected against touch.

Other objects and advantages of this invention will be apparent duringthe course of the following detailed description.

In the accompanying drawing:

FIGURE 1 is a diagrammatic view representing the method and theequipment used in the present invention.

FIGURE 2 is a diagrammatic top view of part of the equipment of FIGURE1.

FIGURE 3 is a fragmentary cross sectional view of the strand formingequipment proper, taken substantially on the line C D of FIGURE 1.

FIGURE 4 is a cross section view showing the formed cigarette strand.

FIGURE 5 is an end elevation of the first part of the equipment.

FIGURE 6 is a cross sectional view of the part of the equipment takensubstantially on the line A-B of FIG- URE 1.

Principally, the equipment of the present invention comprises thefollowing parts and elements:

The apparatus of the invention is mounted upon a suitable base orfoundation 4. Cut tobacco is pneumatically fed through a delivery tube 1to a chute 2 which is mounted on flexible spring type supportingelements 6-6. The air stream can escape at 53. The laterally flexibleelements 66 are mounted upon high voltage insulators 41 carried by thebase 4. The chute 2 is relatively narrow and vibrates and oscillatesunder influence of an alternating current electromagnet 3 mounted on thebase 4 which attracts the conductor 5 attached to the chute 2. The chute2 reciprocates. The arrow shown in the chute 2 of FIGURE 1 designatesthe direction of travel of the stream of cut tobacco. An aspiration box7 constructed of insulating materials is located at the end of chute 2to assist travel of the cut tobacco. A second vibrating and oscillatingchute 18 of about V-shape cross section is mounted upon laterallyflexible spring sets 19 which in turn are mounted upon high voltageinsulators 20, shown in FIGURE 1. The travel of the tobacco along chute18 is in the direction of the arrow shown in the chute 18 of FIGURE 1.This chute 18 is reciprocated by means of an alternating currentelectromagnet 21 which normally attracts the member 22 carried byinsulator 23 attached to the bottom movable portion of the chute 18shown in FIGURE 1. A plate 18* immediately below chute 18 has connectedthereto bolt and terminal means 2425. This chute 18 and its plate 18 areconnected to the negative pole of a grounded high voltage direct currentsource of about 20,000 volts to 80,000 volts. A toothed cylinder 8operating on shaft 9 assists the tobacco from chute 2 into chute 18. Awiper 45 supported by a frame cross piece 10 cleans the cylinder 8.

Above chute 18 is mounted a continuously running endless belt 40supported forwardly upon rollers 55 and shafts 54 and rearwardlysupported upon rollers 13 and 14 mounted on shafits 12. The lower run ofthis belt 40 lies immediately beneath a metallic plate 15 which may besupported upon brackets 39 of the frame of the machine as by bolts 17.Connectors or terminals 16 are provided. The belt 40 operates in thedirection shown by the arrow in FIGURE 1. It is longer than theoscillating chute 18, and projects forwardly therefrom as shown inFIGURE 1. As a matter of fact endless belt 40 extends in part over acontinuously running lower belt 30 trained over a roller 29 mounted inan insulation bushing 28 operating on shaft 27. Cigarette-wrapping papermay be fed over the top of the belt 30. It will be noted that themetallic plate 15 ends at a location immediately above the belt 30 wherebelt 30 extends over the top of the roller 29. A second metallic plate32 may be mounted by cross frame piece 49 and an insulator 46 over thebelt 40 in advance of the plate 15 and spaced therefrom. It has a boltand terminal connection 41-48. This plate 32 must be charged opposite tothe charge of plate 15 and in case the charge of plate 18 is negativeand plate 15 positive, plate 32 will be negatively charged.

In operation, a cut tobacco stream 53 drizzles down tube 1 and is fedinto the chute 2. The cut tobacco is assisted in travel by vibration ofthe chute 2, the air stream and toothed wheel 8, and enters the chute 18which is smaller in width (see FIG. 2) than the chute 2. The

vibrating or oscillating conveyance line has been divided into twoseparate chutes 2 and 18 because the first vibrating chute 2 may be heldstationary. The Width of the second vibrating or oscillating 'chute 18must not exceed the width of the belt 40 arranged above its top but by avery small amount. Chute 18 must not be too narrow for directing feed oftobacco. The tobacco fibers will be negatively charged and carriedupward from chute 18 to the under running side of belt 40; the upperbelt being positively charged through plate 15 and its connectors. Dueto their oppositely charged condition the tobacco fibers will beattracted by and adhere to the lower face or run of the upper belt 40and form a tobacco fleece of satisfactory density. The upper belt 40carries the tobacco fleece to the locus of the endless lower belt 30which is arranged at a distance (k therebelow. At the end of the plate15 the fleece 34 adhering to the lower face of the upper belt 40 vwlldrop at the location 42., onto the vlower belt 30, in the form of thewanted tobacco strand,

because of negative charge of plate 32. At this stage, the wrappingpaper 33 can be fed onto the belt 30 which also carries the strands. Thewrapping paper may be applied at a later stage of manufacture, but insuch case, the tobacgo strand has to be rendered more compact andequalize If desired an accelerating grid or ionizer can be used betweenthe chute 18 and the lower run of the belt 40 directly above chute 18 inorder to assist in lift of the tobacco. The grid wires 36 are fixed onrails 37. This s mounted on the supporting bracket arrangements 39,shown in FIGURE 6 through intermediary of mounting pieces 38 andinsulators 44. Grid wires 36 will be given positive high voltage andwill electrostatically draw the tobacco fibers from the vibrating oroscillating chute 18. The tobacco fibers 35 will now enter into thepotential field corresponding to the grid and will be carried upwardlyas a result of the applied acceleration. Finally they will be attractedby the upper belt 40 the plate 15 of which, under these circumstances,has a negative charge of much higher-current source than plate 18 andwill adhere to the belt 40 in the manner above explained. The plate 32now must have a positive charge.

There are different possibilities with regard to the production of therequired electrostatic field. It is of no importance whether thepositive side or the negative side is grounded. Moreover, the potentialschosen in the present description are to be considered possiblesolutions only. The potential of the metallic plate 32 must, withrespect to load (positive or negative), always be opposite to that ofthe metallic plate 15 so that the tobacco fleece may fall. The forcesresulting from the potential corresponding to the metallic plate 32 mustbe such that they are just sufficient for neutralization of the loadpreviously applied to the tobacco fibers. To this end a relatively lowvoltage (some thousand volts) will be suflicient.

The neutralization of the load concerned may be effected also by the useof other means, such as: a high frequency field, radioactive substances,or the like (the so-called antistatics).

The material'to be used for construction of belt 46 must be capable ofadopting the potentials corresponding (1 to the metallic plates 15 and32. Thus, preference should be given to a semi-conducting medium. Incase, for instance, the belt is made of rubber or plastic materials,such properties as required may be obtained by proportionate admixtureof suitable conductive materials to the body material of the belt.

The second vibrating or oscillating chute 18 may be constructed withperforations 25 through which a ray of light may be passed so as toreach a photoelectric cell or element. In case the quantity of tobaccois excessive as it passes along chute 18 the ray of light will beinterruptcd through perforations and signal given that the feed oftobacco should be reduced.

The insulators 41, used for the first vibrating or oscillating chute arenot indispensably required, but these insulators maybe useful if it isdesired to avoid an inadmissible discharge of the potentialcorresponding to the second vibrating or oscillating chute 18, throughthe tobacco fibers being fed. In case the first vibrating or oscillatingchute 2 is constructed with the said insulators 41, this chute may bemonitored by placing a suitable electric measuring instrument in serieswith a ground connection.

A still further possibility of controlling the tobacco fiber supply tothe upper belt 40 is the following: the distance (h may be chosengreater than the distance (I1 or vice versa.

The high voltage generating means required for the high voltage supplyto the various parts and elements of the equipment in question are ofconventional design and well known. Generally, such high voltagegenerating means are operated from an alternating current main supply,and, to this effect, cascade connection is preferred, and transformers,rectifiers, and condensers are used.

In the primary circuit of the transformer, provision is generally madefor a cold cathode thyratron which will act as a cutting out relay incase the current intensity existing in the high voltage circuit will forany reason become greater than two milliampers (this value isillustrative only). In such case, the high voltage part of the equipmentwill become dead.

The final or finishing of the cigarette strand may be done in a wellknown manner, by the use of moulding or forming means as shown, forinstance, in FIGURE 4 wherein a member 51 with a channel receives belt30. Members 50 complementary to member 51 are provided with wayscomplementary to the depression of member 51 to define a circularpassageway through which belt 30 will progressively be forced so as toform a closed tube. Such forming will be done in a manner that one sidewill be closed previously to the other one so that the cigarette papermay properly be wrapped around the tobacco strand. Finally, belt 30 willcompletely enclose the cigarette strand in such a way that the crosssection of the tube-like belt will be in the form of a circle.

Various changes in the size, shape and arrangement of parts may be madeto the form of invention herein shown and described, without departingfrom the spirit of the invention or scopeof the claims.

I claim:

1. The method of producing tobacco strands from which cigarettes and thelike may be cut into desired lengths which consists in causing a streamof tobacco fibers to travel along a given path and during such travelelectrostatically causing them to adhere to a traveling belt for thepurpose of securing a tobacco strand of uniform density.

antenna ence and while so traveling causing the strands to be confinedand subsequently by electrostatic means caused to adhere to a travelingbelt for the purpose of securing a tobacco strand of uniform density.

4. The method described in claim 3 in which the strand after formationupon said belt is caused to be electrostatically removed from the beltand compressed into final form and wrapped.

5. Apparatus for the production of tobacco strands from which cigarettesand the like may be cut into desired lengths comprising a travel chutehaving confining side walls, means for feeding a stream of tobaccofibers into said chute, means for moving the tobacco fibers along saidchute, an endless belt mounted above the chute having a portion thereoffacing the chute, and electrostatic means for causing the tobaccostrands to be lifted from the chute onto a facing surface of the endlessbelt.

6. Apparatus as described in claim 5 in which the electrostatic meanscomprises oppositely charged means for the chute and for the belt tocause the tobacco strands to be lifted from the chute onto the belt.

7. Apparatus for producing tobacco strands from which cigarettes and thelike may be cut into desired lengths comprising a compacting chutehaving a passageway therealong which opens upwardly, means for causingtobacco fibers to fall into said chute and to travel therealong, a beltsuperposed over said chute, and electrostatic means having potentials ofopposite value for the chute and belt in facing relation for causing thestrand to belifted from the chute onto the belt and travel therewith.

8. Apparatus as described in claim '7 in which a second trough providingbelt is provided below the first mentioned belt located beyond the locusof the aforementioned chute, antistatic means for causing the strand todrop from the first mentioned belt into the trough of the secondmentioned belt, and means for subsequently compressing and wrapping saidstrand.

9. Apparatus for producing tobacco strands from which cigarettes and thelike may be cut into desired lengths comprising a supporting frame, achute, means flexibly mounting the chute for oscillatory movement uponsaid frame, electromagnetic means for oscillating the chute, means forfeeding a stream of tobacco fibers into the chute wherein it is advancedby such oscillation, a second chute in advance of the first mentionedchute having a fiber compressing channel therein and into which thetobacco fibers fall from the first mentioned chute, means mounting thesecond chute for oscillatory movement, electromagnetic means for causingoscillation of the second chute and thereby causing travel of thetobacco strands therealong, an endless belt mounted above the secondchute having a run thereof facing the channel of the second chute,electrostatically operated means for causing the fibers compressed inthe second chute to lift onto the facing surface of the belt, and meansfor subsequently removing said strand from the belt and compacting andwrapping the same.

10. Apparatus for producing tobacco strands from which cigarettes andthe like may be cut into desired lengths comprising a supporting frame,a chute, means pacting channel therein opening upwardly, oscillation ofthe first mentioned chute causing the tobacco fibers to move into thesecond chute channel, means mounting the second chute for flexibleoscillatory movement, means for causing oscillation of the second chutefor travel of the tobacco strands therealong, an cndiess belt mountedabove the second chute having a run thereof facing the channel of thesecond chute, electrostatically operated means for causing the fibersmolded in the second chute to lift onto the outer facing surface of thebelt, a second belt mounted in spaced relation below the first mentionedbelt, antistatic means to causes the fibers carried by the firstmentioned belt to drop onto the facing run of the second mentioned belt,and means to subsequently compact and wrap the fibers into a strand.

11. Apparatus for the production of tobacco strands from whichcigarettes and the like may be cut into desired lengths comprising achute having a passageway open therealong at the top thereof, means forcausing travel of tobacco fibers along said passageway, a belt having arun thereof facing the open passageway of said chute and locatedthereabove, electrostatic means to cause lifting of the tobacco fibersfrom the chute onto the belt comprising means to electrostaticallycharge the chute and belt with the same positive or negative charge butwith the belt charge larger than the chute charge, and a grid locatedbetwen the electrostatic means of the chute and belt and of a differentcharge than said chute and belt to accelerate and cause the lifting ofthe strands from the chute onto the belt.

12. Apparatus as described in claim 11 in which a second belt havingstrand receiving means is located below the first mentioned belt, andantistatic means for the second belt to cause the strand from the firstmentioned belt to fall upon said second mentioned belt for traveltherewith.

13. Apparatus for producing bulk type strands of tobacco from whichcigarettes can be readily cut into desired lengths comprising asupporting frame, a conveyor mounted upon the frame for conveyingtobacco fibers therealong, a second conveyor positioned above the firstmentioned conveyor with a portion thereof travelling in the samedirection as the tobacco fibers on the first mentioned conveyor,electrostatic means including positive and negative plates associatedwith the two conveyors for causing the lifting of fibers of tobacco intoposition in strand form upon the second conveyor for travel therewith,and an accelerating ionizer located between the first and secondmentioned conveyors to assist in lifting the tobacco fibers from thefirst conveyor to the second conveyor.

14. Apparatus as defined in claim 13 in which a third conveyor ispositioned below the second. mentioned conveyor and beyond an end of thefirst mentioned conveyor, and electrostatic means for removing thetobacco strand from the second mentioned conveyor at a location beyondsaid first mentioned conveyor.

References fitted in the file of this patent UNITED STATES PATENTS1,977,991 Hawkins Oct. 23, 1934 2,442,880 Schwartz June 8, 19482,468,827 Kennedy et a1. May 3, 1949 2,576,882 Koole et a1 Nov. 27, 1951FOREIGN PATENTS 762,467 Great Britain Nov. 28, 1956

5. APPARATUS FOR THE PRODUCTION OF TOBACCO STRANDS FROM WHICH CIGARETTES AND THE LIKE MAY BE CUT INTO DESIRED LENGHTS COMPRISING A TRAVEL CHUTE HAVING CONFINING SIDE WALLS, MEANS FOR FEEDING A STREAM OF TOBACCO FIBERS INTO SAID CHUTE, MEANS FOR MOVING THE TOBACCO FIBERS ALONG SAID CHUTE, AN ENDLESS BELT MOUNTED ABOVE THE CHUTE HAVING A PORTION THEREOF FACING THE CHUTE, AND ELECTROSTATIC MEANS FOR CAUSING THE TOBACCO STRANDS TO BE LIFTED FROM THE CHUTE ONTO A FACING SURFACE OF THE ENDLESS BELT. 